Kentucky bluegrass

ABSTRACT

A variety of Kentucky bluegrass having a good level of disease resistance and in particular to the leaf spot diseases. The variety provides a desirable dark blue green color throughout the growing season, a color which is accented during cool periods of the year as found in spring and fall months. The variety produces a thick dense turf and persists throughout the growing season under a wide range of environmental conditions.

SUMMARY OF THE VARIETY

The present invention relates to a new and distinct variety of Poa pratensis which has been designated Ba 62-55-M and is now named Merit Kentucky bluegrass. Merit plant material was one of several biotypes selected out of an old established turf area in southern California. Turf performance evaluations of these types were made which resulted in selecting the best turf type. This final selection resulted in one plant type which is now called Merit. Seed of Merit was produced first at Marysville, Ohio, then Salem and Gervais, Oreg. This seed was used to plant turf trials for evaluation of turf performance. Variety evaluation trials were established at Marysville, Ohio; Accokeek, Md.; Long Beach and Somis, Calif.; Gervais, Oreg.; St. Louis, Mo.; Bolton, Mass. and the province of Ontario, Canada.

Merit Kentucky bluegrass reproduces asexually both by propagules (tillers and rhizomes) and disseminules (modified coryopses produced by agomospermy) and has consistently produced progeny plants indistinguishable from the mother plant.

Merit has a number of highly desirable characteristics including a good level of resistance to Helminthosporium spp and Sclerotinia homoeocarpa, has a decumbent growth habit and will tolerate low heights of cut. It has a pleasing dark blue green color and produces a good dense turf that persists over a wide range of environmental conditions.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a photograph of Merit Kentucky bluegrass maintained under turf management conditions;

FIG. 2 is a Merit Kentucky bluegrass clone in early spring at Gervais, Oreg.;

FIG. 3 is a Merit Kentucky bluegrass clone after anthesis at Gervais, Oregon; and

FIG. 4 is a Merit Kentucky bluegrass panicle.

DETAILED DESCRIPTION OF THE VARIETY

The morphological characteristics of Merit and other commercially available bluegrass varieties are compared in Table 1. As shown by Table 1, the morphological characteristics of Merit afford a basis for distinguishing it from other bluegrass varieties.

                  TABLE 1                                                          ______________________________________                                         MORPHOLOGICAL COMPARISON OF MERIT AND                                          OTHER KENTUCKY BLUEGRASS VARIETIES                                                                                    No. of                                             No. of  No. of     No. of   Nodes                                   Panicle    Panicle Branches   Spikelets                                                                               Per                                     Length     Branch  Per Whorl  Per Whorl                                                                               Plant                                   Variety                                                                               in cm.  Whorls  Lowest                                                                               3rd  Lowest                                                                               3rd  Stem                              ______________________________________                                         Merit   9.0    8.4     5.4   4.2  52.6  29.6 1.8                               Merion 10.3    7.2     3.4   3.4  42.2  27.6 2.6                               Newport                                                                               10.9    9.4     3.8   3.6  33.6  18.8 2.4                               Bristol                                                                               11.7    8.4     3.4   2.6  38.0  23.2 4.0                                                              Leaf Blade Width*                                       Length of   No. of     Measured 2 cm.                                          Top Internode                                                                              Florets    From end of Boat                                Variety in cm.      Per Spikelet                                                                              Tip Leaf                                        ______________________________________                                         Merit   22.2        4.98       2.50 mn                                         Merion  33.6        3.98       2.07 mn                                         Newport 38.6        3.02       2.39 mn                                         Bristol 34.9        5.42       2.52 mn                                         ______________________________________                                          *Leaf blade width of plants maintained under mowed turf conditions (3.8 c      to 6.4 cm)                                                               

Mowed plots have been evaluated under turf conditions in many different tests and at numerous locations. Turfgrass performance information presented indicates the distinctiveness of Merit compared to other bluegrass varieties and its desirable characteristics and persistence.

Seed germination rate and seedling establishment are important factors in a new seedling. Kentucky bluegrasses are recognized for their slowness to germinate and establish compared to other turfgrass species. Differences do occur in germination rates between Kentucky bluegrass varieties. The variety Merion has been rated as slow to germinate whereas the variety Park is normally considered as a faster germinating bluegrass variety. In controlled laboratory tests and field evaluations Merit was rated above Merion and equal to Park in controlled conditions and below Park in actual field conditions. See Tables 2, 3 and 4.

                  TABLE 2.                                                         ______________________________________                                         AVERAGE GERMINATION PERCENTAGES OF VARI-                                       OUS KENTUCKY BLUEGRASS VARIETIES UNDER                                         CONTROLLED CONDITIONS USING LABORATORY                                         GERMINATING CABINET.                                                                     Days After Seeding                                                   Variety     7        10       15     21                                        ______________________________________                                         Merit       55%      77%      81%    85%                                       Victa       54%      71%      83%    88%                                       Park        50%      65%      81%    85%                                       Merion      14%      24%      60%    72%                                       ______________________________________                                          Rating Scale: Number indicates percent of seeds that germinated.               Germinating Conditions:                                                        Temperature 15° C. for 16 hours - dark                                  25° C. for 8 hours - light                                              100 seeds per replication - 3 replications                               

                  TABLE 3.                                                         ______________________________________                                         AVERGE GERMINATION PERCENTAGES OF VARI-                                        OUS KENTUCKY BLUEGRASS VARIETIES SEEDED IN -MID SUMMER UNDER FIELD             CONDITIONS.                                                                                Days After Seeding                                                 Variety       6         8         15                                           ______________________________________                                         Merit         0%        25%       78%                                          Victa         0%        42%       78%                                          Park          0%        43%       84%                                          Merion        0%        19%       65%                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent germination made by visual estimates of three         replications.                                                            

                  TABLE 4.                                                         ______________________________________                                         AVERAGE GERMINATION PERCENTAGES OF                                             VARIOUS KENTUCKY BLUEGRASS VARIETIES                                           SEEDED IN LATE FALL UNDER FIELD CONDITIONS.                                                Days After Seeding                                                 Variety       8         21        32                                           ______________________________________                                         Merit         0%        59%       78%                                          Victa         0%        80%       90%                                          Park          0%        70%       83%                                          Merion        0%        37%       64%                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent germination by visual estimates of three              replications.                                                            

Leafspot (Helminthosporium spp) diseases cause severe plant damage and thinning of bluegrass turf in most locations in the Northern United States and Canada during the months of April, May and June of each year. Table 5 provides leaf spot information in the spring on two year old turf grown at Marysville, Ohio. Merion and Fylking are recognized as having an acceptable and a good level of resistance to leaf spot diseases. The common types of Kentucky bluegrass varieties such as Kenblue are quite susceptible to leaf spot disease. In Table 5 Merit is seen to be equal to or slightly lower in resistance than Merion or Fylking but significantly more resistant than Kenblue.

                  TABLE 5.                                                         ______________________________________                                         LEAF SPOT (Helminthosporium spp) INCIDENCE                                     OF TWO YEAR OLD TURF OF VARIOUS                                                KENTUCKY BLUEGRASS VARIETIES.                                                              Percent Leaf Spot                                                  Variety       April     May       June                                         ______________________________________                                         Merit         15%       23%       25%                                          Kenblue       50%       60%       50%                                          Merion        15%       20%       15%                                          Fylking       20%       20%       20%                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with leaf spot.              

Rating leaf spot diseases for the entire growing season in two consecutive years Merit again demonstrates that it has good resistance compared to other known varieties. See Tables 6 and 7.

                  TABLE 6.                                                         ______________________________________                                         AVERAGE LEAF SPOT (Helminthosporium spp)                                       INCIDENCE OF ONE YEAR OLD TURF                                                 OF VARIOUS KENTUCKY BLUEGRASS VARIETIES.                                                    Avg. Percent Leaf Spot Incidence                                  Variety      for Entire Year                                                   ______________________________________                                         Merit        22%                                                               Kenblue      48%                                                               Merion       30%                                                               Pennstar     25%                                                               ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with leaf spot.              

                  TABLE 7.                                                         ______________________________________                                         AVERAGE LEAF SPOT (Helminthosporium spp) INCIDENCE                             OF TWO YEAR OLD TURF OF VARIOUS                                                KENTUCKY BLUEGRASS VARIETY.                                                                 Avg. Percent Leaf Spot Incidence                                  Variety      for Entire Year                                                   ______________________________________                                         Merit        31%                                                               Kenblue      63%                                                               Merion       28%                                                               Pennstar     30%                                                               ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with leaf spot.              

Good leaf spot resistance was also noted in 3 year old turf plots at Accokeek, Maryland. (Table 8).

                  TABLE 8.                                                         ______________________________________                                         LEAFSPOT (Helminthosporium spp) INCIDENCE OF THREE                             YEAR OLD TURF OF VARIOUS BLUEGRASS                                             VARIETIES AT ACCOKEEK, MARYLAND.                                               Variety           Percent Leaf Spot                                            ______________________________________                                         Merit             13%                                                          Kenblue           60%                                                          Merion             8%                                                          Victa             10%                                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with leaf spot.              

Further demonstrating that Merit has a good level of leaf spot resistance over a wide range of environmental conditions seedings were installed in various locations in Ontario, Canada. Table 9 provides leaf spot resistance data of one year old turf in Ontario, Canada, again indicating that the level of resistance is comparable to known resistant varieties.

                  TABLE 9.                                                         ______________________________________                                         LEAF SPOT (Helminthosporium spp)                                               INCIDENCE IN EARLY SUMMER OF ONE YEAR                                          OLD TURF IN ONTARIO, CANADA, OF VARIOUS                                        KENTUCKY BLUEGRASS VARIETIES                                                   Variety           Percent Leaf Spot                                            ______________________________________                                         Merit             10%                                                          Kenblue           44%                                                          Merion            10%                                                          Flyking            4%                                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with leaf spot.              

Dollar spot (Sclerotinia homoeocarpa) is unsightly and can cause damage if infestation is severe. Dollar spot normally occurs in mid to late summer on Kentucky bluegrass and progresses from very small initial spots of dead turf to circular, straw colored areas 2 to 3 inches in diameter. Affected leaves at first show yellow-green blotches, which become water-soaked and finally bleach to a strain colored tan. Merit has shown good resistance to dollar spot with minimum amount of infestation during peak times of the year. Tables 10 and 11 show a good level of dollar spot resistance of Merit compared to other varieties. Fylking and Nugget are normally considered as being susceptible varieties and the common types such as Kenblue being resistant.

                  TABLE 10.                                                        ______________________________________                                         DOLLARSPOT (Sclerotinia homoeocarpa) INCIDENCE                                 OF TWO YEAR OLD TURF OF VARIOUS                                                KENTUCKY BLUEGRASS VARITIES                                                    Variety           Percent Dollar Spot                                          ______________________________________                                         Merit             4%                                                           Kenblue           0%                                                           Nugget            20%                                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with dollar spot.            

                  TABLE 11.                                                        ______________________________________                                         DOLLAR SPOT (Sclerotinia homoeocarpa) INCIDENCE OF                             VARIOUS KENTUCKY BLUEGRASS VARIETIES AT                                        ACCOKEEK, MARYLAND                                                             Variety           Percent Dollar Spot                                          ______________________________________                                         Merit             16%                                                          Kenblue            7%                                                          Fylking           42%                                                          Nugget            23%                                                          Merion            11%                                                          Bristol            5%                                                          ______________________________________                                          Rating Scale:                                                                  Number indicates percent of leaves infected with dollar spot.            

Merit can be characterized as moderately slow to green up in early spring (Tables 12 and 13).

                  TABLE 12.                                                        ______________________________________                                         EARLY SPRING GREEN UP OF VARIOUS                                               KENTUCKY BLUEGRASS VARIETIES                                                   Variety           Early Spring Color                                           ______________________________________                                         Merit             4.1                                                          Kenblue           6.4                                                          Vantage           6.4                                                          Victa             4.1                                                          Nugget            1.8                                                          ______________________________________                                          Rating Scale:                                                                   1 = straw colored                                                             10 = dark green.                                                         

                  TABLE 13.                                                        ______________________________________                                         EARLY SPRING GREEN UP OF VARIOUS                                               KENTUCKY BLUEGRASS VARIETIES AT                                                ACCOKEEK, MARYLAND                                                             Variety           Early Spring Color                                           ______________________________________                                         Merit             3.0                                                          Vantage           4.0                                                          Kenblue           4.3                                                          Merion            2.8                                                          ______________________________________                                          Rating Scale:                                                                   1 = straw colored                                                             10 = dark green.                                                         

Kenblue and Vantage are known to be one of the first to break winter dormancy and turn green with Merion being late and Nugget very late. When greening is complete Merit has a very dark distinctive blue-green color in the spring compared to other varieties. The depth of its color is shown in Table 14.

                  TABLE 14.                                                        ______________________________________                                         SPRING COLOR OF VARIOUS BLUEGRASS VARIETIES                                    AFTER COMPLETE WINTER DORMANCY HAS                                             BEEN BROKEN AT ACCOKEEK, MARYLAND                                              Variety             Spring Color                                               ______________________________________                                         Merit               9.5                                                        Vantage             8.0                                                        Kenblue             7.5                                                        Merion              9.3                                                        ______________________________________                                          Rating Scale:                                                                   1 = straw colored                                                             10 = dark green.                                                         

Merit has a moderate to low vertical growth habit which makes its use as a turfgrass quite acceptable. Clippings are not excessive when maintained at a turf cutting height and mowed at normal frequent intervals such as 7 to 10 days during active growth. This moderate vertical growth habit can be demonstrated from seedling stage to turf use conditions to mature plant height when seed heads are produced (Tables 15, 16 and 17).

                  TABLE 15.                                                        ______________________________________                                         SEEDLING GROWTH HABIT SIX                                                      WEEKS AFTER SEEDING                                                            Variety            Growth Habit                                                ______________________________________                                         Merit              1.8                                                         Kenblue            3.4                                                         Vantage            2.5                                                         Bristol            1.8                                                         ______________________________________                                          Rating Scale:                                                                  1 = low growing                                                                4 = tall.                                                                

                  TABLE 16.                                                        ______________________________________                                         PLANT HEIGHT REGROWTH OF VARIOUS BLUEGRASS                                     VARIETIES ONE WEEK AFTER MOVING                                                AT 38 mm IN AUGUST                                                             Variety          Plant Height in mm                                            ______________________________________                                         Merit            86                                                            Kenblue          96                                                            Merion           77                                                            Bristol          69                                                            Newport          92                                                            ______________________________________                                          Rating Scale:                                                                  Number indicates length of leaf from ground level to end of leaf.        

                  TABLE 17                                                         ______________________________________                                         MATURE PLANT HEIGHT INCLUDING PANICLE                                          OF VARIOUS KENTUCKY BLUEGRASS VARIETIES                                        GROWN AT MARYSVILLE, OHIO                                                      Variety      Mature Plant Height in Centimeters                                ______________________________________                                         Merit        42 cm.                                                            Bristol      47 cm.                                                            Park         67 cm.                                                            Kenblue      64 cm.                                                            Merion       44 cm.                                                            Bonnieblue   36 cm.                                                            ______________________________________                                          Rating Scale:                                                                  Number indicates length of plant from ground to top of panicle.          

Turf quality, a rating taking all turfgrass performance characteristics together and assigning it a value, was measured at Ontario, Canada; Accokeek, Md. and Marysville, Ohio. A rating scale of 1 to 4 was used with 4 being the best turf. Merit is rated as moderate to good performance in all locations, outperforming the common type varieties and slightly below the recognized improved types (Tables 18, 19 and 20).

                  TABLE 18.                                                        ______________________________________                                         AVERAGE TURF QUALITY RATING FOR                                                ENTIRE GROWING SEASON OF ONE YEAR                                              OLD TURF IN ONTARIO, Canada                                                                  Avg. Turf Quality Ratings for                                    Variety       Entire Growing Season                                            ______________________________________                                         Merit         2.1                                                              Kenblue       1.8                                                              Merion        2.2                                                              Fylking       2.3                                                              ______________________________________                                          Rating:                                                                        1 - Poor                                                                       4 - Excellent.                                                           

                  TABLE 19.                                                        ______________________________________                                         TURF QUALITY OF TWO YEAR OLD TURF                                              OF VARIOUS KENTUCKY BLUEGRASS VARIETIES                                        IN MAY AT MARYSVILLE, OHIO.                                                    Variety             Turf Quality                                               ______________________________________                                         Merit               2.0                                                        Bristol             2.5                                                        Kenblue             1.5                                                        Newport             1.9                                                        Fylking             2.0                                                        ______________________________________                                          Rating Scale:                                                                  1 - Poor                                                                       4 - Excellent.                                                           

                  TABLE 20.                                                        ______________________________________                                         AVERAGE TURF QUALITY FOR ENTIRE                                                GROWING SEASON OF TWO YEAR OLD                                                 TURF AT ACCOKEEK, MARYLAND                                                     Variety             Turf Quality                                               ______________________________________                                         Merit               2.6                                                        Merion              2.8                                                        Victa               2.9                                                        Kenblue             2.0                                                        ______________________________________                                          Rating scale:                                                                  1 - Poor                                                                       4 - Excellent.                                                           

Ten randomly selected seeds of various varieties were laid end to end to obtain total length of the 10 seeds. Merit was shortest in length (27.5 mm) compared to five other varieties. In measuring these same ten seeds as to width by placing them side by side Merit was second widest (7.5 mm) of the group (Table 21), therefore indicating that Merit seed may be distinguished as being a short wide seed. Merit is further distinguished in that it exhibits high seed-set and high seed yield.

                  TABLE 21.                                                        ______________________________________                                         SEED LENGTH AND WIDTH OF TEN RANDOMLY                                          SELECTED SEEDS LAYED END TO END                                                AND SIDE BY SIDE RESPECTIVELY OF                                               VARIOUS KENTUCKY BLUEGRASS VARIETIES                                           Variety      Length in mm  Width in mm                                         ______________________________________                                         Merit        27.5 mm       7.5 mm                                              Fylking      29.8 mm       7.2 mm                                              Park         29.3 mm       6.5 mm                                              Kenblue      29.0 mm       6.7 mm                                              Bristol      28.7 mm       8.5 mm                                              ______________________________________                                    

In seed yield trials under same growing conditions at Gervais, Oreg., differences were noted between varieties in respect to time in heading and anthesis compared to other varieties evaluated (Tables 22 and 23).

                  TABLE 22.                                                        ______________________________________                                         PERCENT HEADING AT DIFFERENT DATES                                             OF VARIOUS KENTUCKY BLUEGRASS                                                  VARIETIES AT GERVAIS, OREGON                                                   Variety                                                                               April 29 May 3   May 7 May 10                                                                               May 17                                                                               May 19                               ______________________________________                                         Merit                    2    25    75     95                                  Vantage                                                                               40       90      95    95    100   100                                  Victa                    2    10    45     95                                  Bristol                                                                                5       10      25    90    95    100                                  Windsor         10      50    90    95    100                                  ______________________________________                                          Rating Scale:                                                                  Number indicates percent of plants that are heading out.                 

                  TABLE 23.                                                        ______________________________________                                         PERCENT ANTHESIS AT DIFFERENT DATES OF                                         VARIOUS KENTUCKY BLUEGRASS                                                     VARIETIES AT GERVAIS, OREGON                                                   Variety                                                                               May 21   May 25  May 27 May 30                                                                               June 2                                                                               June 4                              ______________________________________                                         Merit            1      25     25    50    100                                 Vantage                                                                               25       40      60     100                                             Victa                    1     30    30    100                                 Bristol                                                                               40       80      90     100                                             Windsor                  5     30    50    100                                 ______________________________________                                          Rating Scale:                                                                  Number indicates percent of plants that are flowering.                    

What is claimed and desired to be secured by Letters Patent is:
 1. A variety of bluegrass plant, substantially as shown and described, characterized particularly by a high level of resistance to disease and especially leaf spot disease, a desirable dark blue-green color throughout the growing season but particularly during cool periods of the year, a thick dense turf and persistance under a wide variety of environmental conditions. 